1. Field of the Invention
The present invention relates to a modeling system for designing a mechanical apparatus such as an automobile, a robot, or an aircraft. More specifically, the present invention relates to a system, method and program for processing a math equation used in a modeling system.
2. Description of Related Art
Heretofore, a simulation modeling tool such as MATLAB®/SIMULINK® has been used to create and test a model. Such a model thus created and tested is thereafter implemented on a real machine. Modeling techniques using MATLAB®/SIMULINK® are described in a large number of patent application publications such as Japanese Patent Application Publication No. 2005-222420.
Meanwhile, modeling of a mechanical apparatus by use of SysML, which is an extension of UML, has recently begun as disclosed in Japanese Patent Application Publication No. 2009-176010.
In MATLAB®/SIMULINK®, the behavior of a model results in a differential equation in many cases, and the behavior or a constraint of an element of a model is also described using a math equation in UML/SysML.
In the aforementioned cases, how to handle the described math equation model still remains as a challenge to be solved, as discussed in Japanese Patent Application Publication No. Hei 7-281714.
As a control strategy for designing a certain product, there is a demand for determining whether a certain complex math equation model can be more simply expressed when a system description designed on the basis of general evaluation functions is used in specific modeling. Such a demand arises because when setting a complex math equation model without any simplification, it leads to a complex structure and sometimes causes problems such as an increase in the material cost and the manufacturing cost. In this respect, describing an equivalent function using a simpler math equation model, if possible, is very significant in terms of cost savings.
However, a problem in a control strategy design by SysML or other modeling tools is that criterions for the appropriateness of the level of detail are unclear for a system description using a math equation or SIMULINK®.
For example, how detailed of a description is needed to describe a math equation such as an internal block diagram as a constraint in SysML, or a system element as a SIMULINK® model has been dependent on an aspect where the modeling is used or a subjective view of the developer of the model.
In addition, in modeling of a control portion in focus, the modeling using a system description designed on the basis of general evaluation criterions alone causes the model of the control target in focus to have meaning in a wide range. Thus, an excessively complex control system is likely to be designed in this case. In order to avoid such a situation, whether a portion that can be simplified (hereinafter, referred to as a “simplifiable portion”) exists or not needs to be determined on the basis of quantitative criterions for the appropriateness of the level of detail of the modeling. Such a technique, however, has been unknown so far.